/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.email.activity;

import com.android.email.Email;
import com.android.email.ResourceHelper;
import com.android.email.data.ThrottlingCursorLoader;
import com.android.emailcommon.Logging;
import com.android.emailcommon.provider.EmailContent;
import com.android.emailcommon.provider.EmailContent.Message;
import com.android.emailcommon.provider.EmailContent.MessageColumns;
import com.android.emailcommon.utility.TextUtilities;
import com.android.emailcommon.utility.Utility;

import android.content.Context;
import android.content.Loader;
import android.database.Cursor;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.CursorAdapter;

import java.util.HashSet;
import java.util.Set;


/**
 * This class implements the adapter for displaying messages based on cursors.
 */
/* package */ class MessagesAdapter extends CursorAdapter {
    private static final String STATE_CHECKED_ITEMS =
            "com.android.email.activity.MessagesAdapter.checkedItems";

    /* package */ static final String[] MESSAGE_PROJECTION = new String[] {
        EmailContent.RECORD_ID, MessageColumns.MAILBOX_KEY, MessageColumns.ACCOUNT_KEY,
        MessageColumns.DISPLAY_NAME, MessageColumns.SUBJECT, MessageColumns.TIMESTAMP,
        MessageColumns.FLAG_READ, MessageColumns.FLAG_FAVORITE, MessageColumns.FLAG_ATTACHMENT,
        MessageColumns.FLAGS, MessageColumns.SNIPPET
    };

    public static final int COLUMN_ID = 0;
    public static final int COLUMN_MAILBOX_KEY = 1;
    public static final int COLUMN_ACCOUNT_KEY = 2;
    public static final int COLUMN_DISPLAY_NAME = 3;
    public static final int COLUMN_SUBJECT = 4;
    public static final int COLUMN_DATE = 5;
    public static final int COLUMN_READ = 6;
    public static final int COLUMN_FAVORITE = 7;
    public static final int COLUMN_ATTACHMENTS = 8;
    public static final int COLUMN_FLAGS = 9;
    public static final int COLUMN_SNIPPET = 10;

    private final ResourceHelper mResourceHelper;

    /** If true, show color chips. */
    private boolean mShowColorChips;

    /** If not null, the query represented by this group of messages */
    private String mQuery;

    /**
     * Set of seleced message IDs.
     */
    private final HashSet<Long> mSelectedSet = new HashSet<Long>();

    /**
     * Callback from MessageListAdapter.  All methods are called on the UI thread.
     */
    public interface Callback {
        /** Called when the use starts/unstars a message */
        void onAdapterFavoriteChanged(MessageListItem itemView, boolean newFavorite);
        /** Called when the user selects/unselects a message */
        void onAdapterSelectedChanged(MessageListItem itemView, boolean newSelected,
                int mSelectedCount);
    }

    private final Callback mCallback;

    public MessagesAdapter(Context context, Callback callback) {
        super(context.getApplicationContext(), null, 0 /* no auto requery */);
        mResourceHelper = ResourceHelper.getInstance(context);
        mCallback = callback;
    }

    public void onSaveInstanceState(Bundle outState) {
        Set<Long> checkedset = getSelectedSet();
        long[] checkedarray = new long[checkedset.size()];
        int i = 0;
        for (Long l : checkedset) {
            checkedarray[i] = l;
            i++;
        }
        outState.putLongArray(STATE_CHECKED_ITEMS, checkedarray);
    }

    public void loadState(Bundle savedInstanceState) {
        Set<Long> checkedset = getSelectedSet();
        for (long l: savedInstanceState.getLongArray(STATE_CHECKED_ITEMS)) {
            checkedset.add(l);
        }
    }

    /**
     * Set true for combined mailboxes.
     */
    public void setShowColorChips(boolean show) {
        mShowColorChips = show;
    }

    public void setQuery(String query) {
        mQuery = query;
    }

    public Set<Long> getSelectedSet() {
        return mSelectedSet;
    }

    public boolean isSelected(MessageListItem itemView) {
        return mSelectedSet.contains(itemView.mMessageId);
    }

    @Override
    public void bindView(View view, Context context, Cursor cursor) {
        // Reset the view (in case it was recycled) and prepare for binding
        MessageListItem itemView = (MessageListItem) view;
        itemView.bindViewInit(this);

        // Load the public fields in the view (for later use)
        itemView.mMessageId = cursor.getLong(COLUMN_ID);
        itemView.mMailboxId = cursor.getLong(COLUMN_MAILBOX_KEY);
        final long accountId = cursor.getLong(COLUMN_ACCOUNT_KEY);
        itemView.mAccountId = accountId;
        itemView.mRead = cursor.getInt(COLUMN_READ) != 0;
        itemView.mIsFavorite = cursor.getInt(COLUMN_FAVORITE) != 0;
        itemView.mHasInvite =
            (cursor.getInt(COLUMN_FLAGS) & Message.FLAG_INCOMING_MEETING_INVITE) != 0;
        itemView.mHasAttachment = cursor.getInt(COLUMN_ATTACHMENTS) != 0;
        itemView.mTimestamp = cursor.getLong(COLUMN_DATE);
        itemView.mSender = cursor.getString(COLUMN_DISPLAY_NAME);
        itemView.mSnippet = cursor.getString(COLUMN_SNIPPET);
        itemView.mSubject = cursor.getString(COLUMN_SUBJECT);
        itemView.mSnippetLineCount = MessageListItem.NEEDS_LAYOUT;
        itemView.mColorChipPaint =
            mShowColorChips ? mResourceHelper.getAccountColorPaint(accountId) : null;

        if (mQuery != null && itemView.mSnippet != null) {
            itemView.mSnippet =
                TextUtilities.highlightTermsInText(cursor.getString(COLUMN_SNIPPET), mQuery);
        }
    }

    @Override
    public View newView(Context context, Cursor cursor, ViewGroup parent) {
        //return mInflater.inflate(R.layout.message_list_item, parent, false);
        MessageListItem item = new MessageListItem(context);
        item.setVisibility(View.VISIBLE);
        return item;
    }

    public void toggleSelected(MessageListItem itemView) {
        updateSelected(itemView, !isSelected(itemView));
    }

    /**
     * This is used as a callback from the list items, to set the selected state
     *
     * <p>Must be called on the UI thread.
     *
     * @param itemView the item being changed
     * @param newSelected the new value of the selected flag (checkbox state)
     */
    private void updateSelected(MessageListItem itemView, boolean newSelected) {
        if (newSelected) {
            mSelectedSet.add(itemView.mMessageId);
        } else {
            mSelectedSet.remove(itemView.mMessageId);
        }
        if (mCallback != null) {
            mCallback.onAdapterSelectedChanged(itemView, newSelected, mSelectedSet.size());
        }
    }

    /**
     * This is used as a callback from the list items, to set the favorite state
     *
     * <p>Must be called on the UI thread.
     *
     * @param itemView the item being changed
     * @param newFavorite the new value of the favorite flag (star state)
     */
    public void updateFavorite(MessageListItem itemView, boolean newFavorite) {
        changeFavoriteIcon(itemView, newFavorite);
        if (mCallback != null) {
            mCallback.onAdapterFavoriteChanged(itemView, newFavorite);
        }
    }

    private void changeFavoriteIcon(MessageListItem view, boolean isFavorite) {
        view.invalidate();
    }

    public static Loader<Cursor> createLoader(Context context, long mailboxId) {
        if (Email.DEBUG_LIFECYCLE && Email.DEBUG) {
            Log.d(Logging.LOG_TAG, "MessagesAdapter createLoader mailboxId=" + mailboxId);
        }
        return new MessagesCursorLoader(context, mailboxId);

    }

    static private class MessagesCursorLoader extends ThrottlingCursorLoader {
        private final Context mContext;
        private final long mMailboxId;

        public MessagesCursorLoader(Context context, long mailboxId) {
            // Initialize with no where clause.  We'll set it later.
            super(context, EmailContent.Message.CONTENT_URI,
                    MESSAGE_PROJECTION, null, null,
                    EmailContent.MessageColumns.TIMESTAMP + " DESC");
            mContext = context;
            mMailboxId = mailboxId;
        }

        @Override
        public Cursor loadInBackground() {
            // Determine the where clause.  (Can't do this on the UI thread.)
            setSelection(Utility.buildMailboxIdSelection(mContext, mMailboxId));

            // Then do a query.
            return Utility.CloseTraceCursorWrapper.get(super.loadInBackground());
        }
    }
}